This invention relates to screen panels, and in particular to screen panels used in vibratory screening operations.
In a vibratory screening operation, material which is to be screened is deposited on a vibrating screen deck. It is now common practice for the screen decks to have a frame and for the actual screening surface to be provided by a large number of individual screen panels which are mounted to the frame. It is also common practice for the individual panels to be moulded in a suitable grade of polyurethane.
All screen panels undergo wear in use and have to be replaced when they are no longer able to perform an accurate screening operation. A problem with polyurethanes is that they give off toxic isocyanate gas when incinerated. For this reason material processing plants where screening operations are carried out, such as mine processing plants in which mined ore is processed, tend merely to dump worn panels at large dumpsites rather than incinerating them. However modern mining regulations prohibit such dumping and this means that mine operators are obliged to find ways to deal with the polyurethane employed in worn screen panels.